My buddy is a adult that is 5 foot tall and 125 lbs and has been riding a CR 85. He now wants a 4 stroke and is looking at CRF 150 R's Is he big enough for a CRF 250 R if he put a lowering link on the rear shock? Or would he be better off with a 150R? He wants to be able to throw it around, but I am afraid he will run out of power on a 150R and spend a fortune chaising more HP. What do you think?